Studies On The Molecular Genetic Diversity Of Rice And Its Progenies Of Distant Hybridization

The genetic polymorphism of nuclear and chloroplast of wild rice, cultivated riceand its Progenies of Distant Hybridization was detected using molecular markers. Thegenetic polymorphism, genetic relationship in species and genetic law of theProgenies of Distant Hybridization were discussed According to the diversity. Themain results were as follows:1. Genetic polymorphism of rice chloroplast DNAThe chloroplast DNA of non-AA wild rice was japonica-type using two lengthdiversity markers(ORF100 and ORF29-TrnCGCA) of chloroplast DNA. Abundantpolymorphism in different species was found in two instable regions (intron of rps16gene and TrnTUGU-TrnLUAA spacer). Cluster diagram of rice and finger map ofevery species (all tested species) determined from the diversity of intron of rps16 geneand TrnTUGU-TrnLUAA spacer were built. Furthermore, the chloroplast DNA alsowas studied more to assure which was indica-type or japonica-type utilizing fourmarkers exited in intron of rps16 gene and TrnTUGU-TrnLUAA spacer, the result ofthree markers showed that the chloroplast DNA of non-AA wild rice werejaponica-type and the result of one markers showed that they were indica-type. It alsoshowed that there existed differentiation between the sequence of tested material andthe markers, some aberrance has been produced.2. Genetic polymorphism of rice nuclear DNA11 SSR Primers that can generate clear and highly polymorphic bands werescreened from 65 primers and employed in the present study, and generated total 104bands, average 9.5 bands per primer. At the same time, 166 polymorphic bands weredetected with 8 ISSR primer pairs which were screened from 43 primer pairs, average20.8 bands per primer. The average SSR-based genetic distance (GD) among ricematerials investigated was 1.96(0.98～2.94) while average ISSR-based GD was 2.39(1.00～3.79). Two sets of GD data showed significantly positive correlation, andthe two cluster diagrams based on ISSR and ISSR respectively were very similar,which indicated that either ISSR or SSR marker could efficiently detect the geneticdiversity of rice.Among the 104 polymorphic bands detected by 11 SSR primers, there are 74bands originated from the non-AA wild rice, account for 71.2ï¼…. And there are 113 bands originated from the non-AA wild rice Among the 166 polymorphic bandsdetected by 8 SSR primers, account for 68.7ï¼…. The result shows there have abundantdiversity in non-AA wild rice, which Can supply a mass of favorable gene for thebreeding of rice.3. The construction and analysis of cross population and backcrosspopulation of O. sativa×O. grandiglumisThe cross population and backcross population of O. sativa×O. grandiglumiswere constructed through Immature Embryo Rescue, the offspring of backcross havethick stem, high biomass, big stigma, and flowering at 6: 30AM, which can be used inthe theoretical study and rice breeding. Using 14 premiers detected 20 testedmaterial(Involve the parents and hybrid offspring), The result show only 21.4ï¼…in theF₁(O. sativa×O. grandiglumis) have two bands from the parents, 46.4ï¼…just appearthe band of cultivated rice and 25ï¼…appear the band of O. grandiglumis, 7.2ï¼…presentnew bands which are different from the bands of parents, which suggest someinteraction and adjustment probably happened between the two different genome inthe somatic cell. The result detected backcross offspring showed the bands originatedfrom the O. gradiglumis decrease and even disappear.